In the related art, lubricant compositions containing base oils are often used for improving a sliding property between various members. Particularly, a lubricant composition containing a fluorine-based polymer as a base oil is used in a wide range of temperature from high to low temperatures, since it is chemically stable and has a low pour point due to a much greater binding energy between a fluorine atom and a carbon atom than a binding energy between a carbon atom and each of hydrogen, oxygen and chlorine atoms.
For example, Patent Document 1 discloses a grease composition suitable for a rolling bearing that contains a perfluoropolyether oil as a base oil and contains melamine cyanurate as a thickener with an amount of melamine cyanurate being at least 10% by mass with respect to the total of the grease composition.
Patent Document 2 discloses a lubricant composition containing perfluoropolyether and organic ultrafine particles (ultra-fine polymer).
Furthermore, Patent Document 3 discloses a fluorine-based grease obtained by adding at least one of an aliphatic dicarboxylic acid metal salt, a monoamide monocarboxylic acid metal salt and a monoestercarboxylic acid metal salt as a thickener to a perfluoropolyether base oil, thus having an improved wear resistance, leak resistance and cleanliness as well as cost effectiveness.
Recently, for automotive parts, household electric appliances, electronic information devices and office automation appliances, resin members are more commonly used as gears and sliding members as a result of efforts in reducing weight and cost.
As a lubricant composition which can be preferably used for a sliding section between resin members or between a resin member and a metal member, Patent Document 4 discloses a lubricating grease composition that contains a base oil such as poly-α-olefin, a thickener and a solid lubricant that includes melamine cyanurate (MCA) and polytetrafluoroethylene (PTFE), characterized in that a blending amount of a sum of MCA and PTFE with respect to the total weight of grease is within a range of 0.1-25% by weight and a blending ratio between MCA and PTFE is within a range of MCA/PTFE (ratio by weight)=0.05-50, and having a lubricating function (low dynamic friction coefficient) as well as a quiescence function (high static friction coefficient).